This application claims priority from Australian provisional application 2014 901036 (filed on 24 Mar. 2014), the entirety of which is incorporated by reference.
Incorporated herein by reference in its entirety is the Australian provisional application entitled “Mesh”, filed on 24 Mar. 2015 and having the Australian National University as the Applicant and Vincent Craig, David Russell Nisbet, Antonio Tricoli, and William Wong Sai Yau as Inventors.
In many applications it is necessary to apply a coating to a surface. In some instances it would be desirable to form the coating independently of the surface and then apply the coating to the surface in a separate step. This is however not always practicable using currently available technology. This is particularly so when the coating is a nanostructured coating, as such coatings are commonly fragile.
For example, high specific surface area (SSA) films may be used for various purposes, e.g. super-hydrophobic coatings. Super-hydrophobic or super-hydrophilic coatings are often extremely mechanically fragile. Therefore such coatings are commonly prepared by directly forming the coating on a substrate.
A disadvantage of prior art processes in which a coating is assembled on a substrate is that such processes commonly require large infrastructure such as furnaces and chemical/physical vapour deposition facilities. A further disadvantage of assembling a coating on a substrate is that the mechanical and chemical properties of the coating cannot be optimised independently from the final properties of the substrate. The present invention aims to address one or both of these disadvantages.
The potential applications of the present invention are very widespread, from nanostructured coatings for fuel cells, conductive electrodes (e.g. transparent conductive electrodes), dye sensitized solar cells and diffuse reflective mirrors, to bio-compatible coatings to promote cell growth and transparent coatings for controlled wetting properties. Potential applications also include microfluidic devices.
Regarding super-hydrophobicity, in nature, the most renowned example of super-hydrophobicity belongs to that of Nelumbo, the lotus plant from which the “lotus leaf effect” is named, albeit the presence of a multitude of biological variants. More recently, Rosa, the rose was also found to exhibit super-hydrophobic behaviours. However, unlike the low adhesion super-hydrophobicity demonstrated by the lotus leaf, the rose petal exhibits highly adhesive super-hydrophobic properties (the “rose petal effect”).
In many instances it is not convenient or even feasible to produce nanostructured surfaces on a desired substrate. It would therefore be desirable to be able to transfer a nanostructured layer from the substrate on which it was formed to a substrate on which it is to be used. However such transfer is difficult due to the generally fragile nature of such layers.
There is therefore a need for a simple, preferably scalable, process for transferring a preformed nanostructured layer onto a target substrate.